In recent years, flat panel displays have gradually replaced conventional cathode ray tube displays. Current flat panel displays include organic light-emitting diode (OLED) displays, plasma display panels (PDPs), crystal displays (LCDs), field emission displays (FEDs), and some other less well-known display configurations. An essential component of these flat panel displays is the thin-film transistor (TFT), which controls the on and off state of each pixel.
Referring to FIG. 1, which schematically illustrates a cross-sectional view of a conventional metal oxide thin film transistor structure, the conventional metal oxide thin film transistor structure 10 includes a substrate 101, a gate electrode 102 disposed on the substrate 101, a semiconductor insulation layer 103 disposed on the substrate 101 and the gate electrode 102, a metal oxide layer 104 disposed on the semiconductor insulation layer 103, and a source electrode 105 and a drain electrode 106 each disposed respectively on the metal oxide layer 104. The source electrode 105 and the drain electrode 106 are formed by performing an etching process on a metal layer. However, in the etching process for forming the source electrode 105 and the drain electrode 106 of the conventional oxide thin film transistor structure 10, the metal oxide layer 104 disposed below the source electrode 105 and the drain electrode 106 tends to be corroded by the etching solution used in the process. Thus, a electrically open may be formed in the metal oxide layer 104.
Therefore, there is a need for improving the quality and production yield of the oxide thin film transistor by preventing a metal etching solution from corroding the metal oxide layer while etching the source electrode and the drain electrode.